Conventional telecommunications equipment design focuses on chassis-based or standalone pizza box-based systems. In such systems, stackable pizza boxes are interconnected with copper cabling or the like for data signaling and control between the individually replaceable modules. As no backplane is thus utilized, power distribution presents significant challenges.
In general, a compact cabling and connector solution is required that leaves space for data signaling and control connectors, as well as associated airflow space and space for removable fans and the like. It is important that reliability and redundancy comparable to that of a backplane is provided, and cable and connector handling and voltage concerns must be addressed. During installation and maintenance, arcing at the power input connectors must be avoided. It is also important to provide an expandable system that does not require the pre-allocation of power distribution ports and rack space. Further, a variety of module heights must be accommodated (e.g., 1 RU, 1.5 RU, 2 RU, 3 RU, and 4 RU) in one stack, without the need for complex cable slack management and storage systems that could result in a mess of wiring. Still further, one solution should address user-specific needs by offering a variety of flexible and upgradable powering options, such as 1:1 (AB) redundancy, N+1 redundancy, and AC/DC power options, as well as accomodating different office feed voltages and amperage ratings, as well as other needs. Finally, spacing tolerances between modules and the considerations associated with EIA rack units and ETSI 25 mm vertical spacing requirements must be accommodated.
Point-to-point cabling addresses some, but not all, of these issues. Thus, more robust power distribution interfaces between individually replaceable modules are required.